Re: Math tools for handout

In message <1119636723.884804.7600@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, jer.hughes@xxxxxxxxx writes 
Thank you both of you for your great advice and replies.

On my website, I have gone to great lengths to make sure the site is
accessible to users across the world (such as offering imperial and
metric scales on both ANSI-A and A4 paper).  Right now this ruler is
formatted for 8.5" x 11", but once I get the kinks worked out I will
draft a separate A4 version very soon!

I've gone to several drafting stores in my community and I can not find
a metric scale ruler to base my drawings on.  I've understood that the
Engineer's Scale is an imperial measuring device (
http://en.wikipedia.org/wiki/Engineer%27s_scale ), but from what I'm
hearing, If I use the 1/5, 1/10 and 1/20 scales in cm units, then it
will be in metric scale?

Would anybody be able to point me to a website that shows the graph of
y=a^x, a>1  and the graph of   y=log_a x, a>1?

As recommended, I will convert the cm ruler to mm, but I'm not
understanding the reason for this.  Is it because when people measure
using a 30cm ruler they are actually using millimeters?

In the UK (and I expect everywhere else), it would be very unusual to actually *perform* a measurement in millimetres. The ruler should be scaled in centimetres (which are numbered 1, 2, 3 ... 11, 12, 13... etc). Millimetre subdivisions (with the 5th one slightly longer) should be provided.
It isn't possible to measure by eye a distance of less than one mm so it is normal to measure x cm + y mm and write this as a measurement of
10x + y mm (no decimal point is required, which avoids a potential source of crashed Mars probes).

For rough measurements, then nearest whole cm is used. 

Thanks again!

Would it help to know that 1" = 25.4 mm exactly (the inch is defined in terms of metric units).

See http://en.wikipedia.org/wiki/Inch#International_inch

--
Jeremy Boden
.

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